In a representatively illustrated embodiment thereof, this invention provides a standing pilot type fuel-fired water heater having incorporated therein a specially designed control algorithm which prevents overheating of water stored in the tank portion of the water heater during non-firing periods of the water heater's main burner.
Fuel-fired water heaters typically have a main fuel burner which is ignited by a smaller pilot burner in response to a sensed demand for heating water stored in a tank portion of the water heater. During “standby” periods of the water heater (when its main burner is not firing), a damper in the flue portion of the water heater is normally held in a closed position and opened upon a subsequent firing of the main burner.
When the water is provided with a “standing” pilot burner, whose flame burns continuously, the possibility exists that the tank water may be undesirably overheated by the hot combustion products continuously generated by the pilot burner. In view of this possibility, a need exists for control apparatus and methods for preventing such overheating. It is to this need that the present invention is primarily directed.